John Deere GT245 losing power

I have a John Deere GT245 that runs for about 10 minutes, then backfires and loses power and runs at abou 70% of the normal full power. I have drained the fuel and put in fresh with sta-bil. I have replaced the plugs, ran sea foam spray thru carb but it's still doing the same thing.....any suggestions?

Update (05/04/2016)

I was double checking things and found there was gas in the oil now, could that help isolate the issue?

How much gas? There is always going to be residual gas seeping past the piston due to all the gas is not being burned off at each combustion cycle. So you may smell a little bit of gas in the oil. But if it looks like dirty apple cider vinegar then you have a problem.

May be running super rich. Does the mower smoke out the muffler?

EasyIFI has a point. Pull off the filter and blow through it. There is a arrow on it showing the direction of flow. A good stream of air should be felt at the other end if it is not clogged. If it is clogged you will know it.

Pull the spark plug and see if is wet after running or black from carbon build up.

4个回答

tomahock31 check your valves (proper clearance) as well as perform a leak down test. Check for worn, stuck or broken piston rings, or worn cylinder bore. There is a whole lot that could be going on and you do want to check this in a systematic manner. My concern is the fuel in the oil. I attached the manual for the FH580V as well as the FH601V (your mower can come with a variety of Kawasaki engines). See if that will help you to narrow it down a bit. John-Deere-GT245.pdf

Just to add to @oldturkey03 , good answer, if carb. equipped with fuel shut off solenoid on the bottom of float bowl, these are known to stick, allowing fuel to leak into crank case. Check and possibly clean or replace solenoid if sticking.

Need to replace the defective electrical fuel shutoff solenoid that's on the bottom of the carburetor. That is your problem, I can almost guarantee it. With age and heat, fuel shutoff solenoids often can fail partially or completely. Either can be detrimental to proper engine operation. Relatively common problem with these engines. Drain the fuel-mixed engine oil from crankcase and replace it with fresh new SAE10w-30 oil to proper level on dipstick. I believe the capacity should be somewhere around 2 quarts or a little less. Change oil filter. You should be all set!

It idles at low speed fine, and high speed just fine with about 70% choke, and sounds good. As soon as I engage the mover or press the hydro foot pedal, it starts to stall out. If I give it into the 90's % choke, it will stay running, but just barely. Disengage the mower and runs not bad again.

Both plugs are firing and a little blackened from the excessive choke.

I've put a new fuel filter, and didn't change anything.

Pulling the pressure side of the fuel pump line off while running there is lots of pressure to the carburetor.